1 4324 141 MICRORNAS IN RHEUMATOID ARTHRITIS: FROM PATHOGENESIS TO CLINICAL IMPACT. OVER THE LAST DECADE, MANY EPIGENETIC MECHANISMS THAT CONTRIBUTE IN THE PATHOGENESIS OF AUTOIMMUNE DISORDERS HAVE BEEN REVEALED. MICRORNAS (MIRNAS) ARE SMALL, NON-CODING, RNA MOLECULES THAT BIND TO MESSENGER RNAS AND DISRUPT THE TRANSCRIPTION OF TARGET GENES. RHEUMATOID ARTHRITIS (RA) IS A CHRONIC SYSTEMIC AUTOIMMUNE DISEASE IN WHICH A PLETHORA OF EPIGENETIC CHANGES TAKE PLACE. CURRENT RESEARCH ON RA EPIGENETICS HAS FOCUSED MAINLY ON MIRNAS. GENETIC VARIANCE OF SOME MIRNA GENES, ESPECIALLY MIR-499, MIGHT PREDISPOSE AN INDIVIDUAL TO RA DEVELOPMENT. ADDITIONALLY, ALTERED EXPRESSION OF MANY MIRNAS HAS BEEN DISCOVERED IN SEVERAL CELLS, TISSUES AND BODY FLUIDS IN PATIENTS WITH RA. MIRNAS EXPRESSION ALSO DIFFERS DEPENDING ON DISEASE'S STAGE AND ACTIVITY. SERUM MIR-22 AND MIR-103A MIGHT PREDICT RA DEVELOPMENT IN SUSCEPTIBLE INDIVIDUALS (PRE-RA), WHILE SERUM MIR-16, MIR-24, MIR-125A AND MIR-223 LEVELS ARE ALTERED IN EARLY RA (DISEASE DURATION <12 MONTHS) PATIENTS COMPARED TO ESTABLISHED RA OR HEALTHY INDIVIDUALS. MOREOVER, SERUM MIR-223 LEVELS HAVE BEEN ASSOCIATED WITH RA ACTIVITY AND DISEASE RELAPSE. WHAT IS MORE, SERUM LEVELS OF SEVERAL MIRNAS, INCLUDING MIR-125B AND MIR-223, COULD BE USED TO PREDICT RESPONSE TO RA TREATMENT. FINALLY, MIRNA ANALOGS OR ANTAGONISTS HAVE BEEN USED AS THERAPEUTIC REGIMENS IN EXPERIMENTAL ARTHRITIS MODELS AND HAVE DEMONSTRATED PROMISING RESULTS. IN CONCLUSION, THE RESEARCH ON THE MIRNA ALTERATIONS IN RA SHEDS LIGHT TO SEVERAL ASPECTS OF RA PATHOGENESIS, INTRODUCES NEW BIOMARKERS FOR RA DIAGNOSIS AND TREATMENT RESPONSE PREDICTION AND OFFERS THE OPPORTUNITY TO DISCOVER NEW, TARGETED DRUGS FOR PATIENTS WITH RA. 2019 2 1136 43 COMPREHENSIVE OVERVIEW OF MICRORNA FUNCTION IN RHEUMATOID ARTHRITIS. MICRORNAS (MIRNAS), A CLASS OF ENDOGENOUS SINGLE-STRANDED SHORT NONCODING RNAS, HAVE EMERGED AS VITAL EPIGENETIC REGULATORS OF BOTH PATHOLOGICAL AND PHYSIOLOGICAL PROCESSES IN ANIMALS. THEY DIRECT FUNDAMENTAL CELLULAR PATHWAYS AND PROCESSES BY FINE-TUNING THE EXPRESSION OF MULTIPLE GENES AT THE POSTTRANSCRIPTIONAL LEVEL. GROWING EVIDENCE SUGGESTS THAT MIRNAS ARE IMPLICATED IN THE ONSET AND DEVELOPMENT OF RHEUMATOID ARTHRITIS (RA). RA IS A CHRONIC INFLAMMATORY DISEASE THAT MAINLY AFFECTS SYNOVIAL JOINTS. THIS COMMON AUTOIMMUNE DISORDER IS CHARACTERIZED BY A COMPLEX AND MULTIFACETED PATHOGENESIS, AND ITS MORBIDITY, DISABILITY AND MORTALITY RATES REMAIN CONSISTENTLY HIGH. MORE IN-DEPTH INSIGHTS INTO THE UNDERLYING MECHANISMS OF RA ARE REQUIRED TO ADDRESS UNMET CLINICAL NEEDS AND OPTIMIZE TREATMENT. HEREIN, WE COMPREHENSIVELY REVIEW THE DEREGULATED MIRNAS AND IMPAIRED CELLULAR FUNCTIONS IN RA TO SHED LIGHT ON SEVERAL ASPECTS OF RA PATHOGENESIS, WITH A FOCUS ON EXCESSIVE INFLAMMATION, SYNOVIAL HYPERPLASIA AND PROGRESSIVE JOINT DAMAGE. THIS REVIEW ALSO PROVIDES PROMISING TARGETS FOR INNOVATIVE THERAPIES OF RA. IN ADDITION, WE DISCUSS THE REGULATORY ROLES AND CLINICAL POTENTIAL OF EXTRACELLULAR MIRNAS IN RA, HIGHLIGHTING THEIR PROSPECTIVE APPLICATIONS AS DIAGNOSTIC AND PREDICTIVE BIOMARKERS. 2023 3 1608 41 DNA METHYLATION-GOVERNED GENE EXPRESSION IN AUTOIMMUNE ARTHRITIS. RHEUMATOID ARTHRITIS (RA) IS A CHRONIC INFLAMMATORY AUTOIMMUNE DISEASE HALLMARKED BY PROGRESSIVE AND IRREVERSIBLE JOINT DESTRUCTION. RA PATHOGENESIS IS A T CELL-REGULATED AND B CELL-MEDIATED PROCESS IN WHICH ACTIVATED LYMPHOCYTE-PRODUCED CHEMOKINES AND CYTOKINES PROMOTE LEUKOCYTE INFILTRATION THAT ULTIMATELY LEADS TO DESTRUCTION OF THE JOINTS. THERE IS AN OBVIOUS NEED TO DISCOVER NEW DRUGS FOR RA TREATMENT THAT HAVE DIFFERENT BIOLOGICAL TARGETS OR MODES OF ACTION THAN THE CURRENTLY EMPLOYED THERAPEUTICS. ENVIRONMENTAL FACTORS SUCH AS CIGARETTE SMOKE, CERTAIN DIET COMPONENTS, AND ORAL PATHOGENS CAN SIGNIFICANTLY AFFECT GENE REGULATION VIA EPIGENETIC FACTORS. EPIGENETICS OPENED A NEW FIELD FOR PHARMACOLOGY, AND DNA METHYLATION AND HISTONE MODIFICATION-IMPLICATED FACTORS ARE FEASIBLE TARGETS FOR RA THERAPY. EXPLORING RA PATHOGENESIS INVOLVED EPIGENETIC FACTORS AND MECHANISMS IS CRUCIAL FOR DEVELOPING MORE EFFICIENT RA THERAPIES. HERE WE REVIEW EPIGENETIC ALTERATIONS ASSOCIATED WITH RA PATHOGENESIS INCLUDING DNA METHYLATION AND INTERACTING FACTORS. ADDITIONALLY, WE WILL SUMMARIZE THE LITERATURE REVEALING THE INVOLVED MOLECULAR STRUCTURES AND INTERACTIONS. FINALLY, POTENTIAL EPIGENETIC FACTOR-BASED THERAPIES WILL BE DISCUSSED THAT MAY HELP IN BETTER MANAGEMENT OF RA IN THE FUTURE. 2019 4 5739 36 SMOKING AND RHEUMATOID ARTHRITIS. RHEUMATOID ARTHRITIS (RA) IS A CHRONIC INFLAMMATORY DISEASE CAUSED BY BOTH GENETIC AND ENVIRONMENTAL FACTORS. SMOKING HAS BEEN IMPLICATED AS ONE OF THE MOST IMPORTANT EXTRINSIC RISK FACTORS FOR ITS DEVELOPMENT AND SEVERITY. RECENT DEVELOPMENTS HAVE SHED LIGHT ON THE PATHOPHYSIOLOGY OF RA IN SMOKERS, INCLUDING OXIDATIVE STRESS, INFLAMMATION, AUTOANTIBODY FORMATION AND EPIGENETIC CHANGES. THE ASSOCIATION OF SMOKING AND THE DEVELOPMENT OF RA HAVE BEEN DEMONSTRATED THROUGH EPIDEMIOLOGIC STUDIES, AS WELL AS THROUGH IN VIVO AND ANIMAL MODELS OF RA. WITH INCREASED USE OF BIOLOGICAL AGENTS IN ADDITION TO STANDARD DISEASE-MODIFYING ANTIRHEUMATIC DRUGS (DMARDS), THERE HAS BEEN INTEREST IN HOW SMOKING AFFECTS DRUG RESPONSE IN RA TREATMENT. RECENT EVIDENCE SUGGESTS THE RESPONSE AND DRUG SURVIVAL IN PEOPLE TREATED WITH ANTI-TUMOUR NECROSIS FACTOR (ANTI-TNF) THERAPY IS POORER IN HEAVY SMOKERS, AND POSSIBLE IMMUNOLOGICAL MECHANISMS FOR THIS EFFECT ARE PRESENTED IN THE CURRENT PAPER. 2014 5 4282 41 MICRORNA AND EXOSOME: KEY PLAYERS IN RHEUMATOID ARTHRITIS. RHEUMATOID ARTHRITIS (RA) IS KNOWN AS ONE OF IMPORTANT AUTOIMMUNE DISORDERS WHICH CAN LEAD TO JOINT PAIN AND DAMAGE THROUGHOUT BODY. GIVEN THAT INTERNAL (IE, GENETIC AND EPIGENETIC ALTERATIONS) AND EXTERNAL FACTORS (IE, LIFESTYLE CHANGES, AGE, HORMONES, SMOKING, STRESS, AND OBESITY) INVOLVED IN RA PATHOGENESIS. INCREASING EVIDENCE INDICATED THAT CELLULAR AND MOLECULAR ALTERATIONS PLAY CRITICAL ROLES IN THE INITIATION AND PROGRESSION OF RA. AMONG VARIOUS TARGETS AND MOLECULAR SIGNALING PATHWAYS, MICRORNAS (MIRNAS) AND THEIR REGULATORY NETWORKS HAVE KEY ROLES IN THE RA PATHOGENESIS. IT HAS BEEN SHOWED THAT DEREGULATION OF MANY MIRNAS INVOLVED IN DIFFERENT STAGES OF RA. HENCE, IDENTIFICATION OF MIRNAS AND THEIR SIGNALING PATHWAYS IN RA, COULD CONTRIBUTE TO NEW KNOWLEDGE WHICH HELP TO BETTER TREATMENT OF PATIENTS WITH RA. BESIDES MIRNAS, EXOSOMES HAVE BEEN EMERGED AS KEY MESSENGERS IN RA PATHOGENESIS. EXSOSOMES ARE NANOCARRIERS WHICH COULD BE RELEASED FROM VARIOUS CELLS AND LEAD TO CHANGING OF BEHAVIORS RECIPIENT CELLS VIA TARGETING THEIR CARGOS (EG, PROTEINS, MESSENGER RNAS, MIRNAS, LONG NONCODING RNAS, DNAS). HERE, WE SUMMARIZED SEVERAL MIRNAS INVOLVED IN RA PATHOGENESIS. MOREOVER, WE HIGHLIGHTED THE ROLES OF EXOSOMES IN RA PATHOGENESIS. 2019 6 2294 42 EPIGENETIC REGULATION IN THE PATHOGENESIS OF SJOGREN SYNDROME AND RHEUMATOID ARTHRITIS. AUTOIMMUNE RHEUMATIC DISEASES, SUCH AS SJOGREN SYNDROME (SS) AND RHEUMATOID ARTHRITIS (RA), ARE CHARACTERIZED BY CHRONIC INFLAMMATION AND AUTOIMMUNITY, WHICH CAUSE JOINT TISSUE DAMAGE AND DESTRUCTION BY TRIGGERING REDUCED MOBILITY AND DEBILITATION IN PATIENTS WITH THESE DISEASES. INITIATION AND MAINTENANCE OF CHRONIC INFLAMMATORY STAGES ACCOUNT FOR SEVERAL MECHANISMS THAT INVOLVE IMMUNE CELLS AS KEY PLAYERS AND THE INTERACTION OF THE IMMUNE CELLS WITH OTHER TISSUES. INDEED, THE OVERLAPPING OF CERTAIN CLINICAL AND SEROLOGIC MANIFESTATIONS BETWEEN SS AND RA MAY INDICATE THAT NUMEROUS IMMUNOLOGIC-RELATED MECHANISMS ARE INVOLVED IN THE PHYSIOPATHOLOGY OF BOTH THESE DISEASES. IT IS WIDELY ACCEPTED THAT EPIGENETIC PATHWAYS PLAY AN ESSENTIAL ROLE IN THE DEVELOPMENT AND FUNCTION OF THE IMMUNE SYSTEM. ALTHOUGH MANY PUBLISHED STUDIES HAVE ATTEMPTED TO ELUCIDATE THE RELATION BETWEEN EPIGENETIC MODIFICATIONS (E.G. DNA METHYLATION, HISTONE POST-TRANSLATIONAL MODIFICATIONS, MIRNAS) AND AUTOIMMUNE DISORDERS, THE CONTRIBUTION OF EPIGENETIC REGULATION TO THE PATHOGENESIS OF SS AND RA IS AT PRESENT POORLY UNDERSTOOD. THIS REVIEW ATTEMPTS TO SHED LIGHT FROM A CRITICAL POINT OF VIEW ON THE IDENTIFICATION OF THE MOST RELEVANT EPIGENETIC MECHANISMS RELATED TO RA AND SS BY EXPLAINING INTRICATE REGULATORY PROCESSES AND PHENOTYPIC FEATURES OF BOTH AUTOIMMUNE DISEASES. MOREOVER, WE POINT OUT SOME EPIGENETIC MARKERS WHICH CAN BE USED TO MONITOR THE INFLAMMATION STATUS AND THE DYSREGULATED IMMUNITY IN SS AND RA. FINALLY, WE DISCUSS THE INCONVENIENCE OF USING EPIGENETIC DATA OBTAINED FROM BULK IMMUNE CELL POPULATIONS INSTEAD SPECIFIC IMMUNE CELL SUBPOPULATIONS. 2019 7 1565 34 DNA METHYLATION OF T LYMPHOCYTES AS A THERAPEUTIC TARGET: IMPLICATIONS FOR RHEUMATOID ARTHRITIS ETIOLOGY. RHEUMATOID ARTHRITIS (RA) IS AN AUTOIMMUNE DISEASE THAT CAN CAUSE JOINT DAMAGE AND DISABILITY. EPIGENETIC VARIATION, ESPECIALLY DNA METHYLATION, HAS BEEN SHOWN TO BE INVOLVED IN ALMOST ALL THE STAGES OF THE PATHOLOGY OF RA, FROM AUTOANTIBODY PRODUCTION TO VARIOUS SELF-EFFECTOR T CELLS AND THE DEFECTS OF PROTECTIVE T CELLS THAT CAN LEAD TO CHRONIC INFLAMMATION AND EROSION OF BONES AND JOINTS. GIVEN THE CRITICAL ROLE OF T CELLS IN THE PATHOLOGY OF RA, THE REGULATORY FUNCTIONS OF DNA METHYLATION IN T CELL BIOLOGY REMAIN UNCLEAR. IN THIS REVIEW, WE ELABORATE ON THE RELATIONSHIP BETWEEN RA PATHOGENESIS AND DNA METHYLATION IN THE CONTEXT OF DIFFERENT T CELL POPULATIONS. WE SUMMARIZE THE RELEVANT METHYLATION EVENTS IN T CELL DEVELOPMENT, DIFFERENTIATION, AND T CELL-RELATED GENES IN DISEASE PREDICTION AND DRUG EFFICACY. UNDERSTANDING THE EPIGENETIC REGULATION OF T CELLS HAS THE POTENTIAL TO PROFOUNDLY TRANSLATE PRECLINICAL RESULTS INTO CLINICAL PRACTICE AND PROVIDE A FRAMEWORK FOR THE DEVELOPMENT OF NOVEL, INDIVIDUALIZED RA THERAPEUTICS. 2022 8 2017 49 EPIGENETIC BIOMARKERS IN RHEUMATOLOGY - THE FUTURE? EPIGENETIC CHANGES ARE STABLE MODIFICATIONS OF DNA OR HISTONES THAT PROFOUNDLY ALTER GENE EXPRESSION. THEY CAN BE CHANGED BY ENVIRONMENTAL INFLUENCES AND CAN THEN BE PASSED ON TO DAUGHTER CELLS OR VIA THE GERM LINE TO OFFSPRING. A VARIETY OF CHANGES IN EPIGENETIC MARKS AND IN THE EXPRESSION OF NONCODING RNA HAS BEEN FOUND IN CANCER AS WELL AS IN CHRONIC INFLAMMATORY DISEASES. INTERESTINGLY, IN BOTH DISEASES SIMILAR MECHANISMS AND PATHWAYS ARE AFFECTED ALBEIT OFTEN TO A DIFFERENT EXTENT. DNA METHYLATION IS OFTEN LOST IN REPETITIVE SEQUENCES, WHILE IN PROMOTER REGIONS HYPO- AS WELL AS HYPERMETHYLATION IS FOUND. CHANGES IN MICRORNA LEVELS TYPICALLY AFFECT MICRORNAS THAT ARE CHANGED BY AN INFLAMMATORY ENVIRONMENT, BUT DISEASE SPECIFIC CHANGES HAVE ALSO BEEN FOUND IN THE BLOOD AND VARIOUS CELL TYPES OF PATIENTS WITH RHEUMATOID ARTHRITIS, SYSTEMIC LUPUS ERYTHEMATOSUS AND OTHER RHEUMATIC DISEASES. THEREFORE, CHANGES IN THE EXPRESSION OF MICRORNA IN PARTICULAR, BUT ALSO DEMETHYLATED GENE LOCI, HAVE BEEN PROPOSED AS POTENTIAL BIOMARKERS IN CHRONIC INFLAMMATORY DISEASES AND IN CANCER. POTENTIALLY, THESE CHANGES COULD BE USED FOR EARLY DIAGNOSIS AND ALSO TO PREDICT TREATMENT RESPONSE. UNFORTUNATELY MOST STUDIES IN RHEUMATOLOGY UP TO NOW WERE NOT DESIGNED TO VALIDATE THESE EPIGENETIC CHANGES AS BIOMARKERS. SINCE THE CANCER FIELD IS MUCH MORE ADVANCED IN THE USAGE OF BIOMARKERS FOR DISEASE SUBCLASSIFICATIONS AND SUBSEQUENT THERAPEUTIC DECISIONS, IT IS WORTHWHILE TO TAKE A CLOSER LOOK AT THE BIOMARKERS, METHODS AND PROCEDURES USED IN ONCOLOGY AND TO SEE WHICH OF THESE COULD ALSO BE APPLIED TO PREDICTING DISEASE SEVERITY AND THERAPEUTIC RESPONSE IN RHEUMATIC DISEASES. THIS ARTICLE WILL HIGHLIGHT COMMON EPIGENETIC PATHWAYS ACTIVATED IN CANCER AND VARIOUS RHEUMATIC DISEASES AND SUMMARISE EPIGENETIC CHANGES THAT HAVE THE POTENTIAL TO BECOME BIOMARKERS IN RHEUMATIC DISEASES. 2016 9 4289 32 MICRORNA IN OSTEOARTHRITIS. OSTEOARTHRITIS (OA) IS THE MOST PREVALENT DEGENERATIVE JOINT DISEASE AND IS ACCOMPANIED BY PAIN AND JOINT DYSFUNCTION. ITS CLINICAL TREATMENT TENDS TO BE UNSATISFACTORY. NOVEL TARGETS IN OA INCLUDE GENES THAT ARE INVOLVED IN OA PATHOPHYSIOLOGY AND HAVE BEEN DISCOVERED USING GENE NETWORK, EPIGENETIC AND MICRORNA (MIRNA) APPROACHES. MIRNA HAS BEEN IMPLICATED IN IMPORTANT CELLULAR PROCESSES SUCH AS LIPID METABOLISM, APOPTOSIS, DIFFERENTIATION AND ORGAN DEVELOPMENT. THE IMPORTANCE OF MIRNA REGULATION IN CELLULAR FUNCTION IS BECOMING INCREASINGLY CLEAR AS NEW MIRNA TARGETS ARE REVEALED. THE PRESENT REVIEW SUMMARIZES THE CURRENT EVIDENCE OF THE IMPORTANT ROLE PLAYED BY MIRNA IN DETERMINING THE COMPLEX GENE EXPRESSION PATTERNS OF OA CHONDROCYTES AND THEIR ROLE IN THE REGULATION OF TRANSCRIPTION, AND POSSIBLE DEMETHYLATION MECHANISMS THAT MIGHT BE APPLICABLE IN OA. IN SUMMARY, MIRNA MAY HAVE IMPORTANT DIAGNOSTIC AND THERAPEUTIC POTENTIAL, AND MIGHT PROVIDE A NOVEL MEANS OF TREATING OA. 2011 10 4285 41 MICRORNA EPIGENETIC SIGNATURES IN HUMAN DISEASE. MICRORNAS (MIRNAS) ARE SHORT NON-CODING RNAS THAT ACT AS IMPORTANT REGULATORS OF GENE EXPRESSION AS PART OF THE EPIGENETIC MACHINERY. IN ADDITION TO POSTTRANSCRIPTIONAL GENE SILENCING BY MIRNAS, THE EPIGENETIC MECHANISMS ALSO INCLUDE DNA METHYLATION, HISTONE MODIFICATIONS AND THEIR CROSSTALK. EPIGENETIC MODIFICATIONS WERE REPORTED TO PLAY AN IMPORTANT ROLE IN MANY DISEASE ONSETS AND PROGRESSIONS AND CAN BE USED TO EXPLAIN SEVERAL FEATURES OF COMPLEX DISEASES, SUCH AS LATE ONSET AND FLUCTUATION OF SYMPTOMS. HOWEVER, MIRNAS NOT ONLY FUNCTION AS A PART OF EPIGENETIC MACHINERY, BUT ARE ALSO EPIGENETICALLY MODIFIED BY DNA METHYLATION AND HISTONE MODIFICATION LIKE ANY OTHER PROTEIN-CODING GENE. THERE IS A STRONG CONNECTION BETWEEN EPIGENOME AND MIRNOME, AND ANY DYSREGULATION OF THIS COMPLEX SYSTEM CAN RESULT IN VARIOUS PHYSIOLOGICAL AND PATHOLOGICAL CONDITIONS. IN ADDITION, MIRNAS PLAY AN IMPORTANT ROLE IN TOXICOGENOMICS AND MAY EXPLAIN THE RELATIONSHIP BETWEEN TOXICANT EXPOSURE AND TUMORIGENESIS. THE PRESENT REVIEW PROVIDES INFORMATION ON 63 MIRNA GENES SHOWN TO BE EPIGENETICALLY REGULATED IN ASSOCIATION WITH 21 DISEASES, INCLUDING 11 CANCER TYPES: CARDIAC FIBROSIS, CARDIOVASCULAR DISEASE, PREECLAMPSIA, HIRSCHSPRUNG'S DISEASE, RHEUMATOID ARTHRITIS, SYSTEMIC SCLEROSIS, SYSTEMIC LUPUS ERYTHEMATOSUS, TEMPORAL LOBE EPILEPSY, AUTISM, PULMONARY FIBROSIS, MELANOMA, ACUTE MYELOID LEUKEMIA, CHRONIC LYMPHOCYTIC LEUKEMIA, COLORECTAL, GASTRIC, CERVICAL, OVARIAN, PROSTATE, LUNG, BREAST, AND BLADDER CANCER. THE REVIEW REVEALED THAT HSA-MIR-34A, HSA-MIR-34B, AND HSA-MIR-34C ARE THE MOST FREQUENTLY REPORTED EPIGENETICALLY DYSREGULATED MIRNAS. THERE IS A NEED TO FURTHER STUDY MOLECULAR MECHANISMS OF VARIOUS DISEASES TO BETTER UNDERSTAND THE CROSSTALK BETWEEN EPIGENETICS AND GENE EXPRESSION AND TO DEVELOP NEW THERAPEUTIC OPTIONS AND BIOMARKERS. 2016 11 2232 38 EPIGENETIC MODIFICATIONS OF MIRNAS IN OSTEOARTHRITIS: A SYSTEMATIC REVIEW ON THEIR METHYLATION LEVELS AND EFFECTS ON CHONDROCYTES, EXTRACELLULAR MATRIX AND JOINT INFLAMMATION. OSTEOARTHRITIS (OA) IS A JOINT DISORDER CHARACTERIZED BY PROGRESSIVE DEGENERATION OF CARTILAGE EXTRACELLULAR MATRIX (ECM), CHONDROCYTE HYPERTROPHY AND APOPTOSIS AND INFLAMMATION. THE CURRENT TREATMENTS MAINLY CONCERN PAIN CONTROL AND REDUCTION OF INFLAMMATION, BUT NO THERAPEUTIC STRATEGY HAS BEEN IDENTIFIED AS A DISEASE-MODIFYING TREATMENT. THEREFORE, IDENTIFYING SPECIFIC BIOMARKERS USEFUL TO PREVENT, TREAT OR DISTINGUISH THE STAGES OF OA DISEASE HAS BECOME AN IMMEDIATE NEED OF CLINICAL PRACTICE. THE ROLE OF MICRORNAS (MIRNAS) IN OA HAS BEEN INVESTIGATED IN THE LAST DECADE, AND INCREASING EVIDENCE HAS EMERGED THAT THE INFLUENCE OF THE ENVIRONMENT ON GENE EXPRESSION THROUGH EPIGENETIC PROCESSES CONTRIBUTES TO THE DEVELOPMENT, PROGRESSION AND AGGRESSIVENESS OF OA, IN PARTICULAR ACTING ON THE MICROENVIRONMENT MODULATIONS. THE EFFECTS OF EPIGENETIC REGULATION, PARTICULARLY DIFFERENT MIRNA METHYLATION DURING OA DISEASE, WERE HIGHLIGHTED IN THE PRESENT SYSTEMATIC REVIEW. THE EVIDENCE ARISING FROM THIS STUDY OF THE LITERATURE CONDUCTED IN THREE DATABASES (PUBMED, SCOPUS, WEB OF SCIENCE) SUGGESTED THAT MIRNA METHYLATION STATE ALREADY STRONGLY IMPACTS OA PROGRESSION, DRIVING CHONDROCYTES AND SYNOVIOCYTE PROLIFERATION, APOPTOSIS, INFLAMMATION AND ECM DEPOSITION. HOWEVER, THE POSSIBILITY OF UNDERSTANDING THE MECHANISM BY WHICH DIFFERENT EPIGENETIC MODIFICATIONS OF MIRNA OR PRE-MIRNA SEQUENCES DRIVE THE AGGRESSIVENESS OF OA COULD BE THE NEW FOCUS OF FUTURE INVESTIGATIONS. 2023 12 3031 41 GENETICS OF RHEUMATOID ARTHRITIS. RHEUMATOID ARTHRITIS (RA) IS AN INFLAMMATORY AUTOIMMUNE DISEASE INVOLVING SYMMETRIC JOINTS AND IS GENERALLY CHARACTERIZED BY PERSISTENT PAIN, TENDERNESS, AND DESTRUCTION OF JOINTS. THE VAST MAJORITY OF RA PATIENTS PRODUCE AUTOANTIBODIES, AND IMMUNE CELL INVOLVEMENT IN DISEASE DEVELOPMENT IS WELL RECOGNIZED, AS IS THE CONTRIBUTION OF OTHER TYPES OF CELLS IN SYNOVIAL TISSUE, LIKE FIBROBLASTS. IT IS KNOWN THAT THERE ARE MAJOR GENETIC ASSOCIATIONS WITH THE HLA LOCUS, WHILE MULTIPLE NON-HLA GENETIC VARIANTS DISPLAY RELATIVELY LOW RISK OF RA. BOTH HLA AND NON-HLA ASSOCIATIONS SUGGEST THAT THE PROFILES OF GENETIC ASSOCIATIONS FOR AUTOANTIBODY-POSITIVE VS. AUTOANTIBODY-NEGATIVE RA ARE DIFFERENT. SEVERAL ALLELES OF HLA-DRB1 ARE ASSOCIATED WITH HIGH RISK FOR AUTOANTIBODY-POSITIVE RA, WITH THE STRONGEST RISK CHARACTERIZED BY VALINE AT POSITION 11 OF THE PROTEIN SEQUENCE (HLA-DRB1*04 AND *10 ALLELES). THERE IS A STRONG PROTECTIVE EFFECT FOR THE RISK OF AUTOANTIBODY-POSITIVE RA ASSOCIATED WITH HLA-DRB1*13 ALLELES. ALTHOUGH MAJOR GENETIC ASSOCIATIONS HAVE BEEN KNOWN FOR SEVERAL YEARS, UNDERSTANDING OF THE SPECIFIC MECHANISMS IN THE DEVELOPMENT OF INCREASED RISK OF RA FOR THESE VARIATIONS IS WORK IN PROGRESS. CURRENT STUDIES FOCUS ON THE BINDING OF IMMUNE RECEPTORS INVOLVED IN RECOGNITION OF PUTATIVE PEPTIDES IN ACTIVATION OF T CELLS, AS WELL AS INVESTIGATION OF CELL SIGNALING MECHANISMS. AT LEAST A PART OF RA RISK COULD BE EXPLAINED BY GENE-GENE AND GENE-ENVIRONMENT INTERACTIONS. THERE ARE CURRENTLY MORE THAN 150 CANDIDATE LOCI WITH POLYMORPHISMS THAT ASSOCIATE WITH RA, MAINLY RELATED TO SEROPOSITIVE DISEASE, AND NEW DISCOVERIES ARE ANTICIPATED IN THE FUTURE FROM INVESTIGATION OF DIVERSE HUMAN POPULATIONS. THIS NEW RESEARCH WILL HELP CREATE A STRONG FOUNDATION FOR THE CONTINUING PROCESS OF INTEGRATING GENETIC, EPIGENETIC, TRANSCRIPTOMIC, AND PROTEOMIC DATA IN STUDIES OF RA. 2022 13 3039 31 GENOME ENGINEERING FOR PERSONALIZED ARTHRITIS THERAPEUTICS. ARTHRITIS REPRESENTS A FAMILY OF COMPLEX JOINT PATHOLOGIES RESPONSIBLE FOR THE MAJORITY OF MUSCULOSKELETAL CONDITIONS. NEARLY ALL DISEASES WITHIN THIS FAMILY, INCLUDING OSTEOARTHRITIS, RHEUMATOID ARTHRITIS, AND JUVENILE IDIOPATHIC ARTHRITIS, ARE CHRONIC CONDITIONS WITH FEW OR NO DISEASE-MODIFYING THERAPEUTICS AVAILABLE. ADVANCES IN GENOME ENGINEERING TECHNOLOGY, MOST RECENTLY WITH CRISPR-CAS9, HAVE REVOLUTIONIZED OUR ABILITY TO INTERROGATE AND VALIDATE GENETIC AND EPIGENETIC ELEMENTS ASSOCIATED WITH CHRONIC DISEASES SUCH AS ARTHRITIS. THESE TECHNOLOGIES, TOGETHER WITH CELL REPROGRAMMING METHODS, INCLUDING THE USE OF INDUCED PLURIPOTENT STEM CELLS, PROVIDE A PLATFORM FOR HUMAN DISEASE MODELING. WE SUMMARIZE NEW EVIDENCE FROM GENOME-WIDE ASSOCIATION STUDIES AND GENOMICS THAT SUBSTANTIATES A GENETIC BASIS FOR ARTHRITIS PATHOGENESIS. WE ALSO REVIEW THE POTENTIAL CONTRIBUTIONS OF GENOME ENGINEERING IN THE DEVELOPMENT OF NEW ARTHRITIS THERAPEUTICS. 2017 14 783 28 CELL-SPECIFIC EPIGENETIC DRIVERS OF PATHOGENESIS IN RHEUMATOID ARTHRITIS. RHEUMATOID ARTHRITIS IS A COMPLEX, INFLAMMATORY AUTOIMMUNE DISEASE, WHICH IS CHARACTERIZED BY PAIN, SWELLING AND JOINT DAMAGE DRIVEN BY THE ALTERED BEHAVIOR OF A NUMBER OF DIFFERENT CELL TYPES SUCH AS SYNOVIAL FIBROBLASTS MACROPHAGES AND LYMPHOCYTES. THE MECHANISM UNDERLYING PATHOGENESIS IS UNCLEAR BUT INCREASING EVIDENCE POINTS TO ALTERED EPIGENETIC REGULATION WITHIN THESE CELL TYPES WHICH PROMOTES THE ACTIVATED DESTRUCTIVE BEHAVIOR THAT UNDERLIES DISEASE PATHOGENESIS. THIS REVIEW SUMMARIZES THE KEY EPIGENETIC MODIFICATIONS IN THE MOST IMPORTANT CELLS TYPES IN RHEUMATOID ARTHRITIS, WHICH ARE ASSOCIATED WITH DISEASE ACTIVITY. WE ALSO DISCUSS EMERGING AVENUES OF RESEARCH FOCUSING ON READERS OF EPIGENETIC MARKERS WHICH MAY SERVE TO BE POTENTIAL THERAPEUTIC TARGETS. 2021 15 4845 32 ONE YEAR IN REVIEW 2020: PATHOGENESIS OF RHEUMATOID ARTHRITIS. RHEUMATOID ARTHRITIS (RA) IS A CHRONIC INFLAMMATORY AUTOIMMUNE DISEASE INFLUENCED BY BOTH GENETIC, EPIGENETIC AND ENVIRONMENTAL FACTORS. THE DISCOVERY OF NEW GENE POLYMORPHISMS AND THEIR ASSOCIATION WITH DISEASE SUSCEPTIBILITY HAVE ADDED NEW ELEMENTS TO BETTER CLARIFY RA PATHOGENESIS. IN THE LAST YEAR, IMPORTANT ELEMENTS HAVE BEEN ADDED TO THE CURRENT KNOWLEDGE OF MECHANISMS REGULATING INNATE AND ADAPTIVE IMMUNITY IN RA, LEADING TO DISCOVERING NEW TARGETS FOR THE DEVELOPMENT OF DISEASE-MODIFYING THERAPIES. THUS, IN THIS REVIEW WE SUMMARISE THE NEW INSIGHTS RESULTING FROM A LITERATURE RESEARCH DATA PUBLISHED IN THE LAST YEAR. 2020 16 5372 45 RECENT ADVANCES IN UNDERSTANDING THE PATHOGENESIS OF RHEUMATOID ARTHRITIS: NEW TREATMENT STRATEGIES. RHEUMATOID ARTHRITIS (RA) IS CONSIDERED A CHRONIC SYSTEMIC, MULTI-FACTORIAL, INFLAMMATORY, AND PROGRESSIVE AUTOIMMUNE DISEASE AFFECTING MANY PEOPLE WORLDWIDE. WHILE PATIENTS SHOW VERY INDIVIDUAL COURSES OF DISEASE, WITH RA FOCUSING ON THE MUSCULOSKELETAL SYSTEM, JOINTS ARE OFTEN SEVERELY AFFECTED, LEADING TO LOCAL INFLAMMATION, CARTILAGE DESTRUCTION, AND BONE EROSION. TO PREVENT JOINT DAMAGE AND PHYSICAL DISABILITY AS ONE OF MANY SYMPTOMS OF RA, EARLY DIAGNOSIS IS CRITICAL. AUTO-ANTIBODIES PLAY A PIVOTAL CLINICAL ROLE IN PATIENTS WITH SYSTEMIC RA. AS BIOMARKERS, THEY COULD HELP TO MAKE A MORE EFFICIENT DIAGNOSIS, PROGNOSIS, AND TREATMENT DECISION. BESIDES AUTO-ANTIBODIES, SEVERAL OTHER FACTORS ARE INVOLVED IN THE PROGRESSION OF RA, SUCH AS EPIGENETIC ALTERATIONS, POST-TRANSLATIONAL MODIFICATIONS, GLYCOSYLATION, AUTOPHAGY, AND T-CELLS. UNDERSTANDING THE INTERPLAY BETWEEN THESE FACTORS WOULD CONTRIBUTE TO A DEEPER INSIGHT INTO THE CAUSES, MECHANISMS, PROGRESSION, AND TREATMENT OF THE DISEASE. IN THIS REVIEW, THE LATEST RA RESEARCH FINDINGS ARE DISCUSSED TO BETTER UNDERSTAND THE PATHOGENESIS, AND FINALLY, TREATMENT STRATEGIES FOR RA THERAPY ARE PRESENTED, INCLUDING BOTH CONVENTIONAL APPROACHES AND NEW METHODS THAT HAVE BEEN DEVELOPED IN RECENT YEARS OR ARE CURRENTLY UNDER INVESTIGATION. 2021 17 3038 38 GENOME ENGINEERING FOR OSTEOARTHRITIS: FROM DESIGNER CELLS TO DISEASE-MODIFYING DRUGS. BACKGROUND: OSTEOARTHRITIS (OA) IS A HIGHLY PREVALENT DEGENERATIVE JOINT DISEASE INVOLVING JOINT CARTILAGE AND ITS SURROUNDING TISSUES. OA IS THE LEADING CAUSE OF PAIN AND DISABILITY WORLDWIDE. AT PRESENT, THERE ARE NO DISEASE-MODIFYING OA DRUGS, AND THE PRIMARY THERAPIES INCLUDE EXERCISE AND NONSTEROIDAL ANTI-INFLAMMATORY DRUGS UNTIL TOTAL JOINT REPLACEMENT AT THE END-STAGE OF THE DISEASE. METHODS: IN THIS REVIEW, WE SUMMARIZED THE CURRENT STATE OF KNOWLEDGE IN GENETIC AND EPIGENETIC ASSOCIATIONS AND RISK FACTORS FOR OA AND THEIR POTENTIAL DIAGNOSTIC AND THERAPEUTIC APPLICATIONS. RESULTS: GENOME-WIDE ASSOCIATION STUDIES AND ANALYSIS OF EPIGENETIC MODIFICATIONS (SUCH AS MIRNA EXPRESSION, DNA METHYLATION AND HISTONE MODIFICATIONS) CONDUCTED ACROSS VARIOUS POPULATIONS SUPPORT THE NOTION THAT THERE IS A GENETIC BASIS FOR CERTAIN SUBSETS OF OA PATHOGENESIS. CONCLUSION: WITH RECENT ADVANCES IN THE DEVELOPMENT OF GENOME EDITING TECHNOLOGIES SUCH AS THE CRISPR-CAS9 SYSTEM, THESE GENETIC AND EPIGENETIC ALTERNATIONS IN OA CAN BE USED AS PLATFORMS FROM WHICH POTENTIAL BIOMARKERS FOR THE DIAGNOSIS, PROGNOSIS, DRUG RESPONSE, AND DEVELOPMENT OF POTENTIAL PERSONALIZED THERAPEUTIC TARGETS FOR OA CAN BE APPROACHED. FURTHERMORE, GENOME EDITING HAS ALLOWED THE DEVELOPMENT OF "DESIGNER" CELLS, WHEREBY THE RECEPTORS, GENE REGULATORY NETWORKS, OR TRANSGENES CAN BE MODIFIED AS A BASIS FOR NEW CELL-BASED THERAPIES. 2019 18 4842 38 ONE YEAR IN REVIEW 2017: PATHOGENESIS OF RHEUMATOID ARTHRITIS. RHEUMATOID ARTHRITIS (RA) IS A CHRONIC INFLAMMATORY AUTOIMMUNE DISEASE INFLUENCED BY BOTH GENETIC AND ENVIRONMENTAL FACTORS. IT HAS BEEN POSTULATED THAT A HIGH-RISK GENETIC BACKGROUND, IN COMBINATION WITH EPIGENETIC MARKS AND ENVIRONMENTAL EXPOSURES, LEADS TO A CASCADE OF EVENTS INDUCING SYNOVITIS AND CONSEQUENT DESTRUCTIVE ARTHRITIS. THE CLINICAL PICTURE OF JOINT INVOLVEMENT IN RA IS THE RESULT OF CHRONIC INFLAMMATION OF THE SYNOVIUM, CHARACTERISED BY INTERACTIONS OF RESIDENT CELLS SUCH AS FIBROBLAST-LIKE SYNOVIOCYTES (FLS) WITH CELLS OF THE INNATE (E.G. MACROPHAGES, DENDRITIC CELLS, MAST CELLS AND NK CELLS, NEUTROPHILS) AND ADAPTIVE IMMUNE SYSTEM (E.G. B AND T LYMPHOCYTES). CURRENTLY, OUR UNDERSTANDING OF THE ROLE OF INNATE AND ADAPTIVE IMMUNITY IN THE PATHOGENESIS OF RA IS EXPANDING. THE CONCEPT OF HOW IMMUNE RESPONSES CONTRIBUTE TO THE DISEASE HAS DRAMATICALLY EVOLVED OVER THE LAST 50 YEARS. SHEDDING SOME LIGHT ON THE DIFFERENT ASPECTS OF RA PATHOGENESIS WILL HELP TO IDENTIFY NEW TARGETS FOR THE DEVELOPMENT OF DISEASE-MODIFYING THERAPIES. THUS, IN THIS REVIEW WE REPORT NEW INSIGHTS IN RA PATHOGENESIS, RESULTING FROM A LITERATURE RESEARCH DATE PUBLISHED IN THE LAST YEAR. 2017 19 6624 41 UNDERSTANDING PSORIASIS: ROLE OF MIRNAS. PSORIASIS IS A CHRONIC, IMMUNE-MEDIATED INFLAMMATORY SKIN DISEASE, WITH A MULTIFACTORIAL ETIOLOGY AND IMPORTANT IMMUNOLOGIC, GENETIC AND ENVIRONMENTAL COMPONENTS. PSORIASIS VULGARIS REPRESENTS ITS MOST COMMON FORM, WITH A VARIABLE PREVALENCE ACROSS THE GLOBE. ALTHOUGH ITS PATHOGENESIS REMAINS TO BE FULLY ELUCIDATED, A LACK OF BALANCE IN THE EPIGENETIC NETWORK HAS BEEN SHOWN TO TRIGGER CERTAIN ELEMENTS OF THIS DISEASE, POSSIBLY ALTERING ITS OUTCOME. MICRORNAS ARE SMALL NON-CODING RNA MOLECULES INVOLVED IN RNA-SILENCING AND THE POST-TRANSCRIPTIONAL REGULATION OF GENE EXPRESSION, WHICH ALSO APPEAR TO MEDIATE THE IMMUNE DYSFUNCTION IN PSORIASIS. ALTHOUGH MICRORNA RESEARCH IS A NEW FIELD IN DERMATOLOGY AND PSORIASIS, THERE IS RAPIDLY ACCUMULATING EVIDENCE FOR ITS MAJOR CONTRIBUTION IN THE PATHOGENESIS OF CHRONIC INFLAMMATORY CONDITIONS, INCLUDING PSORIASIS AND OTHER DERMATOLOGICAL DISORDERS. FURTHERMORE, CIRCULATING MIRNAS IDENTIFIED IN PATIENTS' BLOOD SAMPLES HAVE BEEN IDENTIFIED AS PROMISING BIOMARKERS OF DIAGNOSIS, PROGNOSIS OR TREATMENT RESPONSE. EXTENDED INVESTIGATIONS IN THIS FIELD ARE REQUIRED, AS UNTIL NOW, THE EXACT INVOLVEMENT OF MIRNAS IN PSORIASIS HAVE REMAINED TO BE ENTIRELY ELUCIDATED. THIS SHORT REVIEW HIGHLIGHTS A NUMBER OF THE ROLES OF MIRNAS FOUND IN DIFFERENT STAGES OF PSORIASIS. 2018 20 4330 46 MICRORNAS: AN EPIGENETIC TOOL TO STUDY CELIAC DISEASE. THIS ARTICLE SUMMARIZES RECENT FINDINGS ON THE ROLE OF MICRORNAS (MIRNAS) IN BIOLOGICAL PROCESSES ASSOCIATED WITH THE REGULATION OF CHRONIC INFLAMMATION AND AUTOIMMUNITY. MIRNAS ARE SMALL NON-CODING RNA MOLECULES THAT HAVE BEEN RECENTLY EMERGED AS A NEW CLASS OF MODULATORS OF GENE EXPRESSION AT THE POST-TRANSCRIPTIONAL LEVEL. MIRNAS BIND TO COMPLEMENTARY SEQUENCES OF SPECIFIC TARGETS OF MESSENGERS RNA, WHICH CAN INTERFERE WITH PROTEIN SYNTHESIS. WE REVIEWED STUDIES THAT EVALUATED THE EXPRESSION PATTERNS OF MIRNAS IN DIFFERENT AUTOIMMUNE DISEASES, ESPECIALLY IN CELIAC DISEASE (CD). CD IS A CHRONIC ENTEROPATHY TRIGGERED BY GLUTEN PROTEINS, CHARACTERIZED BY ALTERED IMMUNE RESPONSES IN GENETICALLY SUSCEPTIBLE INDIVIDUALS THAT RESULTS IN DAMAGE TO THE BOWEL MUCOSA. CD HAS A HIGH PREVALENCE AND AN EFFECTIVE TREATMENT BY A SPECIFIC DIET ("GLUTEN FREE DIET"). GENETIC FACTORS CONFER SUSCEPTIBILITY BUT DO NOT EXPLAIN THE WHOLE DISEASE, SUGGESTING THAT ENVIRONMENTAL FACTORS DO PLAY A RELEVANT ROLE IN THE DEVELOPMENT OF THE CONDITION.THE EVALUATION OF THE POTENTIAL ROLE OF MIRNA IS OF PARTICULAR INTEREST IN CD GIVEN THAT THESE EPIGENETIC MECHANISMS IN THE PATHOGENESIS OF AUTOIMMUNE AND INFLAMMATORY DISEASES HAVE BEEN RECENTLY DESCRIBED. IMPROVING OUR UNDERSTANDING OF MIRNAS IN CD WILL CONTRIBUTE TO CLARIFY THE ROLE OF ALTERED EPIGENETIC REGULATION IN THE DEVELOPMENT AND COURSE OF THIS DISEASE. 2014